Differentiating left ventricular remodelling in aortic stenosis from systemic hypertension and impact of surgical replacement

(2) Abstract Background Left ventricular (LV) hypertrophy occurs in both aortic stenosis (AS) and systemic hypertension (HTN) in response to wall stress. However, differentiation of hypertrophy due to these two aetiologies is lacking, as well as an understanding of the impact of surgical aortic valve replacement (AVR). The aim was to study the 3-dimensional geometric remodelling pattern in severe AS pre– and post-surgical AVR, and to compare with HTN and healthy controls. Methods Ninety-one subjects (36 severe AS, 19 HTN and 36 healthy controls) underwent cine cardiac magnetic resonance (CMR). CMR was repeated eight months post-AVR (n=18). Principal component analysis (PCA) was performed on the 3-dimensional meshes reconstructed from 109 CMR myocardial contours of 91 subjects at end-diastole. PCA modes were compared across experimental groups. Results A unique AS signature was identified by wall thickness linked to a LV left-right axis shift and a decrease in short axis eccentricity. HTN was uniquely linked to increased septal thickness. Combining these three features had good discriminative ability between AS and HTN (AUC=0.792). The LV left-right axis shift was not reversible post-AVR and was predictive of post-operative LV mass regression (R 2 =0.339, p=0.014). AVR was associated with a reduction in global LV size and correction of short axis eccentricity. Conclusions Unique remodelling signatures can differentiate the aetiology of LV hypertrophy. LV axis shift is characteristic in AS, is not reversible post AVR, predicts mass regression, and is interpreted to be an adaptive mechanism.